Synthetic material containers present an ever expanding problem to waste management throughout the world. Methods for reducing the size of waste material, or possibly more importantly the volume of space that it fills, have been extensively sought. For example empty aluminium cans can simply be crushed and the physical properties of the can ensure that it remains crushed therefore filling a relatively small volume. The plastic/elastic properties of a number of other types of container means that once crushed containers can readily “uncrush” themselves, thus occupying more space.
Prior art in this area suggests several methods for overcoming this problem. Several examples of bellows/concertina sided containers allowing convenient squashing have been proposed. Furthermore, some of these containers contain integral locking devices to hold the containers in a reduced volume. The locking devices in the prior art vary substantially, including threaded screw and nut arrangements, ratchet type arrangements and moulded male/female protrusion/mouldings that can fit snugly together in a “locked” position.